One such system has already been described in French Pat. No. 2 583 186 granted Oct. 20, 1987 and entitled "A system for managing paid-for parking". According to this prior patent, parking is checked on the basis of two items of information which a driver is required to insert in a parking terminal at the beginning of the period during which the vehicle is parked. The first item of information is a vehicle identification number, e.g. the number of the parking space occupied by the vehicle, or preferably, the registration number of the vehicle or a portion thereof. The second item of information is the expiry time for authorized parking. When a checker desires to check that a vehicle is legitimately parked, all the checker has to do is enter the vehicle registration number or the number of the parking space occupied by the vehicle into a portable terminal. In one of various different possible ways, the portable terminal compares the number entered with numbers it contains in its memory and it verifies whether the corresponding expiry time for legitimate parking has elapsed or not.
As clearly explained in the above-mentioned patent, this system makes it possible to considerably simplify checking on paid-for vehicle parking.
However, the nature of the information used for identifying the vehicle can give rise to various drawbacks in some cases. When this information is constituted by the number of a parking space, said spaces must be marked out and numbered in a manner which is still legible after a driver has parked a vehicle in the parking space. This is not always easily done. When the identification is constituted by the vehicle registration number, some drivers may object to a parking terminal storing information over some unverifiable period of time specifying that such-and-such a vehicle was parked at such-and-such a time in such-and-such a location, even when the parking was legitimate. In other words there is a potential problem with invasion of privacy.
An object of the present invention is to provide a system for managing paid-for vehicle parking which retains the advantages of the system described in the above-mentioned patent, but which identifies vehicles without making use either of vehicle registration numbers or of the numbers of parking spaces occupied by vehicles.